Modern football turf is a layered system built from synthetic grass blades (usually polyethylene plastic), a granular infill of crumb rubber and sand, a fabric backing, and a compacted stone base underneath. Each layer serves a different purpose, from mimicking the look and feel of grass to absorbing impacts and draining rainwater. Here’s what goes into each one.
The Grass Blades: Synthetic Fibers
The green “grass” you see on a football field is made from thin ribbons of plastic, most commonly polyethylene. Polyethylene fibers are soft, flexible, and look the most like real grass. They hold up well under cleats and resist fading in sunlight, which is why they’ve become the standard for football at every level.
Nylon is the other major fiber material. It’s stiffer, more durable, and handles extreme heat better than polyethylene, but it feels rougher underfoot and costs more. With proper maintenance, nylon turf can last 15 years or longer. Some fields use a blend of both materials, combining polyethylene’s softness with nylon’s toughness.
On today’s fields, these fibers are cut to a pile height between 40 and 70 millimeters (roughly 1.5 to 2.75 inches), which is tall enough to stand upright and move like natural grass. That’s a dramatic change from the earliest artificial turf, which was a flat nylon carpet barely over a millimeter thick with no infill at all.
The Infill: What’s Between the Blades
Infill is the loose material spread between the synthetic fibers. It’s what gives the field its cushion, keeps the blades standing upright, and determines a lot about how the surface plays. Most football fields use one of two main types, or a combination.
Crumb rubber is the most common infill in professional and college football. It’s made from recycled car and truck tires that are ground into small black granules. Crumb rubber provides good shock absorption and helps simulate the give of natural soil. It can also be coated with colorants or antimicrobial substances to reduce odor and bacterial growth.
Silica sand is the other foundational infill material. High-purity silica sand (above 90% purity) resists crushing and doesn’t absorb bacteria easily. Many fields use sand as a base layer topped with crumb rubber. Coated versions of silica sand exist too, sealed with a thin elastomeric or acrylic layer that further blocks bacteria and improves durability.
A growing number of fields are moving toward organic alternatives. Cork and coconut husk blends, for instance, eliminate the rubber smell and are easier to recycle. These organic infills are typically about 10% to 15% cork and coconut material mixed with 85% to 90% sand. They have a tan or brown appearance rather than black, and they don’t retain heat the way rubber does. The tradeoff is lower stability and a tendency to decompose over time.
The Backing: What Holds It Together
Flip a piece of turf over and you’ll see the backing, a fabric layer that anchors all the synthetic fibers in place. Most systems use a dual-backing approach. First, a latex layer is applied to the underside of the turf for flexibility. Then a polyurethane layer goes on top of that for strength and weather resistance. The combination keeps the fibers locked in even under heavy foot traffic and prevents the turf from tearing or separating at the seams.
The Base: Crushed Stone and Drainage
Underneath the turf carpet sits a compacted stone base, usually 4 to 8 inches deep, that provides structural support and handles drainage. Common base materials include crushed granite (also called decomposed granite), crushed limestone, or a road base mix of crushed stone and fine particles. Each compacts firmly and lets water pass through at different rates.
Drainage matters because water has to move through the turf, through the infill, and down through the base quickly enough to keep the field playable during rain. The turf backing itself is perforated with small holes to let water pass through. In areas with heavy rainfall, fields often add French drains or perforated pipe systems buried beneath the stone base to channel water away faster.
How Turf Has Changed Over Three Generations
The original artificial turf, branded as ChemGrass and later AstroTurf, was installed in the Houston Astrodome in the 1960s. It was a short, dense nylon carpet laid directly over compacted soil with no infill and no cushioning. Players described it as playing on a thin carpet over concrete, and injuries from friction burns and joint impact were common.
Second-generation turf arrived in the 1970s and 1980s with longer fibers, a shock-absorbing pad underneath, and silica sand infill packed to within a few millimeters of the fiber tips. This was a major improvement in cushioning but still felt nothing like grass.
Third-generation turf, the type used on football fields today, introduced crumb rubber infill (alone or mixed with sand), much taller polyethylene fibers, and engineered drainage systems. The result is a surface that plays closer to natural grass while holding up to far more use.
Heat Retention on Synthetic Turf
One well-documented drawback of synthetic turf is how hot it gets. Research from the University of Kansas found that surface temperatures on artificial turf averaged about 95°F compared to 75°F on natural grass, a difference of roughly 20 degrees. Even the air temperature one meter above the turf was measurably warmer. The dark crumb rubber absorbs and radiates heat, which is why some newer fields are shifting to lighter-colored or organic infills.
PFAS in Turf Manufacturing
Some synthetic turf products contain PFAS, a class of industrial chemicals sometimes called “forever chemicals” because they don’t break down in the environment. PFAS have been used in turf manufacturing to resist stains and UV damage. Regulatory pressure is building: Rhode Island, for example, has passed legislation banning the sale of artificial turf containing intentionally added PFAS starting in 2029. As these laws take effect, manufacturers are reformulating their products, but PFAS-free turf is not yet universal across the industry.